tfma.metrics.Preprocessor.SetupContextParam

Allows one to use a context manager to manage DoFn-scoped parameters.

The context will be entered before the DoFn is used and exited when it is discarded, equivalent to the setup and teardown methods of a DoFn. (Note, like teardown, exiting is best effort, as workers may be killed before all DoFns are torn down.)

The object returned from __enter__, if any, will be substituted for this parameter in invocations. Multiple context manager parameters may be specified which will all be evaluated (in an unspecified order).

This can be useful for setting up shared resources like persistent connections to external services for transforms like Map, FlatMap, and Filter where one does not have setup and teardown methods.

Methods

create_and_enter